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Model specific boards => Golf mk5 => Topic started by: paulm007 on 09 August 2007, 09:54

Title: Low RON fuel
Post by: paulm007 on 09 August 2007, 09:54: Have been running my ED30 on 97RON fuel since I bought it, can't seem to get 99RON around here! No problems so far but I was running on fumes the other day on the way back from Liverpool, pulled into a petrol station but they only had normal unleaded (95RON). :huh:

Having read the posts on fuel on here I knew that car would be ok on this, although not ideal so put in Ã‚£15 to keep me going. Well strange things have happened since I did this, and its not my imagination I am sure!

The Ã‚£15 seems to be lasting for a long time, have been averaging 35mpg (a good 5 above my average over the same routes) and yesterday put my foot down and the car almost took off (torque steer in 4th!). :shocked:

Whats going on??
Title: Re: Low RON fuel
Post by: derdle on 09 August 2007, 12:45: Oddly enough lower octane fuels have a higher calorific value so more "energy" in the fuel. The octane rating refers to the level of anti-knock stuff they put in the fuel. Iirc the filler cap on mine shows a preference for 98 but 95 can be used too (the 95 is in a smaller font).
Title: Re: Low RON fuel
Post by: AlanD on 09 August 2007, 12:51: I use 97RON BP Ultimate, havent really seen much in the way of "going faster" (yet). Do get better MPG tho. All this "new fuel" stuff sounds like a load of bollock$ to me.
Title: Re: Low RON fuel
Post by: 2007GTI on 09 August 2007, 13:08: Quote from: aland on 09 August 2007, 12:51
I use 97RON BP Ultimate, havent really seen much in the way of "going faster" (yet). Do get better MPG tho. All this "new fuel" stuff sounds like a load of bollock$ to me.

But FSi engines are different to the Mk4 engines I think you'll find! :nerd:
Title: Re: Low RON fuel
Post by: AlanD on 09 August 2007, 13:33: Yeah I know lol, but whats the deal with Pauls car then? Explain that Mr !
Title: Re: Low RON fuel
Post by: Teutonic_Tamer on 27 August 2007, 20:22: Quote from: aland on 09 August 2007, 13:33
Yeah I know lol, but whats the deal with Pauls car then? Explain that Mr !

Placebo effect ????

Maybe Paul has some kind of "subconcious" fear that the lower grade brew will do damage to his engine, and so he is subconciously driving it more carefully. However, if he is driving it more carefully (ie, not booting it), then the ECU wont have detected any detonation, or knocking, and therefore not needed to retard the ignition timing.

I think this is perfectly valid explanation, based on what Paul wrote in the initial post.